The present invention relates to an image scrolling system of a display device, more particularly to the image scrolling system preferable for use in a portable terminal device.
According system for scrolling letters displayed on a screen of a display device has been employed in a portable terminal device for the purpose of shifting displayed letter sequence(s) up and down or right and left and totally displaying all of the letter sequences on a relatively narrow screen space of a display unit (made up of LCD and the like) due to smallness of the device.
There is used now a scrolling system of displaying letter sequences line by line every time by pushing down an up- or down-scrolling button provided on, e.g., a portable telephone.
As an image-displaying and controlling device intended to scroll images displayed on a screen of a display unit by simple operation, for example, Japanese Patent Kokai Publication JP-A-7-271505/1995 discloses a formulation equipped with scrolling means of changing images displayed on a display screen corresponding to an acceleration detected by acceleration detection means.
However, the aforementioned conventional portable telephone has the following problem.
In the portable telephone, scrolling is done by finger""s action. Thus operation on a scrolling button by single hand is difficult to manage. In most cases of using the portable telephone, the button is operated by the thumb when the portable telephone is held by a single hand. Especially, in case of scrolling with an up- or down-scrolling key, such button operation as to push down the up- or down-scrolling key by the thumb is very burdensome.
Accordingly, the present invention has been made in consideration of the above problem. Its object is to provide a novel scrolling system of displayed letters markedly improved in scrolling system of displayed letters in a portable telephone terminal device.
In order to solve the above problem, a scrolling system of the present invention for scrolling displayed letters features that letters displayed on a display unit are scrolled in a direction detected by shake movement detection means upon shaking the whole device.
Typically, there is provided a scroll controlling system of a display image as set forth in claim 1, 2 or a portable terminal device of claim 7. Other features of the present invention are mentioned in the dependent claims and other claims. The description thereof is incorporated herein by reference. Generally, the detecting shaking direction of the device is carried out by detecting, upon shaking the device, successive contacts of the movable member to one electrode and another electrode disposed in mutually opposite directions of said movable member. The electrode is switched over upon contact of said movable member. At least one electrode is formed as an electrode unit of a pair of electrodes which are switched over upon contact of said movable member.